The present invention relates to a novel apparatus for use with a chisel plow, having a shank which may have a tip member or shovel connected thereto for plowing. More particularly, the invention includes a novel apparatus for preventing damage to the tip member or shovel and the shank when, during plowing, a relatively immovable object, such as a large rock, is encountered.
A chisel plow is a well-known farm implement for use in plowing fields. A chisel plow typically comprises a rigid frame mounted on wheels via wheel supporting struts and a rockshaft transversely journalled upon the frame, and a plurality of plowing tools attached thereto to furrow the soil. The tools comprise shanks which may have integral tips, but usually include separate tip members or shovels fixed thereto. The rock shaft is adapted to be operated for permitting the tools attached thereto to be raised for transporting the plow or lowered for plowing. When, in the course of plowing, the shank or shovel encounters a relatively immovable object, such as a large rock, the rigid construction of the typical chisel plow will cause the shank or shovel to be either broken or sprung out of shape. This will obviously result in considerable expense and loss of time in replacing damaged parts. One solution which has been advanced for this problem, comprises a hinge and shear pin arrangement for attaching the shank to the plow frame. With this arrangement, when the shovel or shank strikes a rock, the force on the shank will cause the shear pin to break, allowing the shank to rotate on the hinge arrangement so as to be removed from the plowing position without damage. The operator must then stop the plowing operation, raise the entire plow out of the work position, and go bbck to the affected shank to remove the sheared pin, put the shank back into the plowing position, and replace the broken shear pin with a new shear pin. Considerable time is consumed by this operation, not to mention the expense of replacement shear pins, especially in the case where the ground being plowed contains many large rocks, necessitating many delays and repairs during the plowing operation.